THz Spectroscopy - Tool towards Viable Solar Technology

The global effort to develop economically viable energy technology would vastly benefit from the ability to directly observe free carriers in candidate materials. A technique that can do this exists. Light within the terahertz regime interacts with free carriers in semi-conductors, metals, conductive polymers etc. In terahertz spectroscopy the full electromagnetic field transmitted through the material of interest is recorded. From this data the free carrier mobility, electron scattering times, carrier lifetimes and carrier dynamics can be determined on a sub-picosecond timescale. Even more importantly, one typically obtains detailed mechanistic understanding into why a probed material has for instance poor electron mobility or high carrier recombination rates. In this poster presentation I will share examples from my current research that demonstrate how THz spectroscopy gives unique insight into solar materials not obtainable through any other technique or experiment. One such example is the details of electron mobility in TiO2 nanotubes (see attached figure). I will also propose a novel spectrometer configuration specifically designed for the development of cost-effective solar materials.